Tuned radial horn



Nov; 19, 1929.

I NVENTOR R. HUTCHISON TUNED RADIAL HORN 'Filed Aug. 4, 1927 R O MB M v 0 Patented Nov. 19, 1929 UNITED STATES PATENT orrics MILLER REESE HUTCHISON, OF WEST ORANGE, NEW JERSEY, ASSIGNOR, BY IESNE ASSIGNMENTS, TO ACOUSTIC PRODUCTS COMPANY, OF NEW YORK, N. Y., A COB:

IPOBATION OF DELAWARE TUNED RADIAL HORN Application filed August a, 1927. Serial no. amazon The invention relates in general to acoustic apparatus, and more particularly to a loud speaker or sound reproducer having faithful and pleasing sound reproducing characteristics.

Horn or ipe resonators do not have the property of resonating satisfactorily fractional harmonics or notes of lower pitch than the fundamental, while they do have the property of resonating quite readily harmonics or overtones of higher pitch than the fundamental.

In loud speakers of the multiple horn type, therefore, in order to obtain notes of great purity throughout the entire musical scale and to reproduce music faithfully, it is desirable to select individual horns which have a fundamental period quite low in the musical scale or spectrum. However, in the case of low pitch open end horns or pipes, these pipes or horns, lwhile resonating all the desired musical notes most satisfactorily, are necessarily of comparatively great length and are therefore, unsatisfactory from a standpoint gives most satisfactor results.

These results and a vantages are obtained, in one form of the invention, by providing a. central sound chamber or casing and a plurality of closed end individual pipe reso nators communicating therewith, each pipe being tuned to a diflerent fundamental note of the chromatic scale. An electromagnetic receiver or telephone unit having a single flexible diaphragm may be connected to one side of the chamber or casing and a hell or flare for delivering the sound may be connected to the other side. The flexible diaphragin readily vibrates in response to the different notes impressed thereon by the electromagnet to set the surrounding medium into appended hereto, the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. l is a section taken on the line 1-1 of Fig. 2; and

Fig. 2 is a section taken on the line 22 of Fig. 1.

In the following description and in the claims parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

4 Like reference characters denote like parts in the several. figures ofthe drawings.

Referring now to the drawing, the device as shown comprises a generally 0 lindrical chamber or casing 1 which is pre erably of small cubic content. Arranged radially around the casing are a pluralit of pipes 2 having their outer ends 3 close and having their inner ends 4 flattened in the direction of the axis of the cylindrical casing, so that the cross section throughout the entire'length of each pipe is substantially constant. The pipes are of difierent lengths to resonate the difierent notes of any desired musical scale, and are preferably arranged to resonate the notes of an octave 1n the chromatic scale, there being twelve pipes, one for each note in the octave.

Connected to one side of the chamber or casing 1 is an electromagnet casing 5 which may be similar to the usual loud s eaker telephone unit comprising the usua magnet 6 having a winding thereon and a diaphragm 7 secured in operative relation thereto. On the other side of the casing 1 from the telephone unit is secured a bell or flare 8 which operates to convey the sound waves which are resonated by the pipes to the surrounding medium. 1 I

Sound pipes do not readily resonate the fractional harmonics below the fundamental, Whereas they resonate quite readily the harmonicsor overtones above the fundamental. It is, therefore, of prime importance, in orderto have pleasing reception, to make the pipes of such lengths that the octave covered thereby is comparatively low in a musical scale. Pipes having closed ends have lengths equal to one-quarter the Wavelength resonated, and therefore the pipes may be contained in a comparatively small space even though the fundamental notes are low in the musical scale and the wavelengths long.

The chamber or casing is made of small cubic content so as not to have any critical eriod of its own within the-range of audibility. The diaphragm is of such nature as to respond readily and to vibrate to all the dili'erent audible frequencies It will be seen that the energy of complex Wave form delivered .to the electromagnet by the electric current will be reproduced faithfully and will give a pleasing effect. Each note is readily transmitted by the flexible diaphragm and is readily resonated by some particular pipe or tube, the note then being delivered by the bell or flare into the surrounding medium. Since each note impressed electrically upon the electromagnet is faithfully transmitted by the acoustic apparatus to the surrounding medium, the original quality of the sound delivered to the electromagnet will be quite unimpaired by the acoustic apparatus and the result will be pleasing to the ear. 1

Although the apparatus has been described as a loud speaker or reproducer and it is intended fundamentally, to be used as such, it will be appreciated that it may be used also as a transmitter. In this case its operation will be reversed, original music or other sound being delivered into the bell or flare and causing variation in the current flowing through the windings of the receiver, as is well understood in the art.

While certain novel features of the invention have been shown. and described and are pointed out in the annexed claim, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

In a loud speaker, a cylindrical hollow casdiflerent note of the chromatic scale and disposed radially around said casing and communicat'ing therewith, said tubes having closed outer ends and being flattened at their inner ends in the direction of the axis of the cylindrical chamber, a sound propagator connected to the back end of said casing, and an outwardly flaring bell connected to the front end of said casing.

Signed at New York, in the county of New York and State of New York, this 2d day of August, A. D. 1927.

MILLER REESE HUTCHISQN.

ing of small cubic content, twelve sound re-.

sonating tubes each arranged to resonate a 

